Acoustic Monitoring for Fluidized Bed Boilers

The newly developed monitor watches the fluidized condition of FBC (Fluidized Bed Combustor), referring to acoustic signals which are collected by heating tubes in the beds and passing to tube acceleration sensors outside the fluidized Beds. The monitor can be applied to FBC easily without any observation hole or special probes, and detects the bad-fluidized region, which requires proper operations for preventing from agglomeration. The monitor adopts the joint time-frequency analysis technique to the acoustic signals as well as considers non-Gaussian properties, on decision making procedure, including skewness and excess of parameter distributions which are the resulting characteristics through the analyses on the time-frequency plain. The monitor has been applied to a 350MWe FBC for testing, and validated through two year operation.